Check out an inverted F-35 firing off a missile to test performance under negative G forces

As the F-35 marches closer to full combat readiness, pilots test the jet in ever more challenging environments, most recently by firing a AIM 9x air-to-air missile while flying upside-down.

"This unique missile launch is a situation we don't expect a pilot to be in very often," read the release. Firing a missile upside-down is nothing new. Fighters have had this capability for decades, and the stealth F-35 shouldn't often find itself in a turning fight with adversaries.

But now they know that if they need to fire a missile while experiencing negative G forces and inverted, they can.

"We want to provide the maximum capability of the F-35 to the fleet to get them where they need to be for training and operational use," said James Shepherd, the test pilot who fired the missile at Patuxent River Navy Base. "This will ensure we meet our promises to deliver the most advanced fifth generation fighter in the world."

Check out the missile in the pictures below:

Courtesy of F-35 Lightning II Joint Program Office

Courtesy of F-35 Lightning II Joint Program Office